SAR Wideband Interference Suppression Method Using Second-Order Multisynchrosqueezing Transform

Abstract

In the current complex electromagnetic environment, the imaging quality of synthetic aperture radar (SAR) may be severely degraded by wideband interference (WBI), which occupies a wide frequency band overlapping with the frequency band of the SAR system, leading to great difficulties in WBI suppression. To address this problem, we propose a method based on the masked second-order multisynchrosqueezing transform (MSST2) to effectively extract WBI from corrupted SAR data. First, the SAR echo is characterized in the time-frequency (TF) domain by the short-time Fourier transform (STFT) with adaptive window width, and a TF mask for the WBI is generated. Then, the energy of the WBI is concentrated with high resolution by MSST2, and the TF mask is refined according to the MSST2 result. Finally, the WBI is accurately reconstructed from the MSST2 result masked by the refined TF mask and is subtracted from the SAR echo. Abundant experimental results for measured SAR data with simulated and real WBI demonstrate the superior performance and practicability of the proposed method.